1. Field of the Invention
This invention relates to improved systems for combustion of fuels and to methods for catalytic promotion of fuel combustion. In one specific aspect the present invention relates to low thermal emissions combustors for gas turbine applications.
2. Brief Description of the Prior Art
Gas turbine combustors require the capability for good combustion stability over a wide range of operating conditions. To achieve low NO.sub.x operation with variations of conventional combustors has required operating so close to the stability limit that not only is turndown compromised, but combustion stability as well. Although emissions can be controlled by use of the catalytic combustors of my U.S. Pat. No. 3,928,961, such combustors typically also have a much lower turndown ratio than conventional combustors with efficient operation limited to temperatures above about 1400 Kelvin with an upper temperature limited not only by NO.sub.x formation kinetics but by catalyst materials survivability, thus limiting use in some applications.
The present invention meets the need for reduced emissions by providing a system for the combustion of fuel lean fuel-air mixtures, even those having exceptionally low adiabatic flame temperatures.